Fix hyperparameter_search doc (#6695)

src/transformers/trainer.py

@@ -780,9 +780,9 @@ class Trainer:
         **kwargs
     ) -> BestRun:
         """
-        Launch an hyperparameter search using ``optuna`` or ``Ray Tune``. The optimized quantity is determined by the
-        method, which is the evaluation loss when no metric is provided, the sum of all metrics otherwise (you can
-        change that behavior by subclassing and overriding this method).
+        Launch an hyperparameter search using ``optuna`` or ``Ray Tune``. The optimized quantity is determined by
+        :obj:`compute_objectie`, which defaults to a function returning the evaluation loss when no metric is provided,
+        the sum of all metrics otherwise.
 
         Args:
             hp_space (:obj:`Callable[["optuna.Trial"], Dict[str, float]]`, `optional`):
@@ -805,7 +805,7 @@ class Trainer:
                 Additional keyword arguments passed along to :obj:`optuna.create_study` or :obj:`ray.tune.run`. For
                 more information see:
 
-                - the documentation of `optuna.create_stufy <https://optuna.readthedocs.io/en/stable/reference/alias_generated/optuna.create_study.html#optuna.create_study>`__
+                - the documentation of `optuna.create_study <https://optuna.readthedocs.io/en/stable/reference/alias_generated/optuna.create_study.html#optuna.create_study>`__
                 - the documentation of `tune.run <https://docs.ray.io/en/latest/tune/api_docs/execution.html#tune-run>`__
 
         Returns: